Fan head swinging device

ABSTRACT

A fan head-swinging device includes a speed reducer and a DC motor. The speed reducer consists of plural gears engaging with each other. The DC motor is fixed behind a housing of a fan, having a spindle fixed on with a small gear engaging with one of the plural gears of the speed reducer. So the shaft of that gear may rotate with a very slow speed suitable to the fan head to swing right and left for a proper angle by controlling the DC motor.

BACKGROUND OF THE INVENTION

[0001] This invention relates to a fan head swinging device, particularly to one capable to swing right and left for any angle.

[0002] A conventional fan head swinging device shown in FIGS. 1 and 2, includes a speed reducer A consisting of plural gears AO rotated by a synchronous motor B, the motor B has no carbon brushes, and a coil B3 powered to excite magnetism to produce a magnetic field to let the rotor BO of the motor B to rotate. Then a spindle B1 is connected to the rotor BO, and a gear B2 is fixed on the spindle B1 and engages one of the plural gears AO of the speed reducer A, causing the head to swing right and left. As the synchronous motor used in the conventional fan has no carbon brushes, which means the excited magnetic field produced between the rotating direction of the rotor BO and the coil B3 has no constant direction. Therefore, the swinging direction of the fan head cannot be controlled as it should be, and the fan head may be liable to swing reverse if it might receive an exterior force. So an outer wind guider C provided in a cool fan shown in FIG. 3 may change its rotating direction if it is touched. Some traditional fan are provided with a control rod D as shown in FIG. 4 for controlling the fan head in changing its swinging direction, owing to the disadvantage of the synchronous motor in impossibility to control a fan head in swinging correctly.

SUMMARY OF THE INVENTION

[0003] The objective of the invention is to offer a fan head swinging device to swing right and left for any angle correctly.

[0004] The feature of the invention is a speed reducer connected to a DC motor capable to control in changing the rotating direction of the motor, and subsequently possible to control accurately the swinging angle of a fan head.

BRIEF DESCRIPTION OF DRAWINGS

[0005] This invention will be better understood by referring to the accompanying drawings, wherein:

[0006]FIG. 1 is a front view of a speed reducer in a conventional fan;

[0007]FIG. 2 is a cross-sectional view of the line 2-2 in FIG. 1;

[0008]FIG. 3 is a front view of a conventional cooling fan;

[0009]FIG. 4 is a side view of a conventional fan;

[0010]FIG. 5 is a front view of a speed reducer in a fan in the present invention;

[0011]FIG. 6 is a cross-sectional view of the line 6-6 in FIG. 5;

[0012]FIG. 7 is a partial view of a cooling fan in the present invention;

[0013]FIG. 8 is a front view of the cooling fan in the present invention; and,

[0014]FIG. 9 is side view of the fan in the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0015] A preferred embodiment of a fan head swinging device in the present invention, as shown in FIGS. 5 and 6, includes a speed reducer 1 consisting of plural conventional gears 10 engaging with each other for reducing speedy rotation of a DC motor so as to reduce rotation speed of a shaft 15 of one of the plural conventional gears of the reducer 1, in other words, swinging speed of the fan head lowered to a very slow one (1000:3 in most fans sold in market). Therefore the fan head may be swung right and left to a preset angle to send proper wind to the swinging scope. The DC motor 12 is located behind a housing 11, having a spindle 12 and a small gear 14 fixed on the spindle 12 and engaging with one of the gears 10 of the speed reducer 1, reducing high rotating speed of the DC motor to a very low speed of the shaft 15 of that gear 10 suitable to swinging speed of the fan head. The DC motor 12 is easily controlled to change its rotating direction. So, accordingly the fan head can be easily controlled in its swinging angle as desired. Then a user may operate the control system to set the swing angle as wanted.

[0016] The fan head swinging device may be utilized in a cooling fan 2, controlling its wind guider 20 to rotate with a constant speed, and a user can set its rotating direction freely by means of controlling rotating direction of the DC motor 12 only. And the control rod 30 used in the conventional fan can be omitted.

[0017] While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention. 

What is claimed is:
 1. A fan head swinging device comprising a speed reducer consisting of plural gears engaging with each other, a DC motor fixed behind a housing of a fan and having a spindle, a small gear fixed on said spindle and engaging one of said plural gears of said speed reducer, high rotating speed of said DC motor reduced to a vary slow one by means of said speed reducer, said fan head swinging right and left for a proper angle by means of said speed reducer and said DC motor, a swinging angle possible to be set by a user owing to said DC motor easily controlled. 